<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <!-- 让网页自适应手机屏幕的宽度，即完美视口 -->
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      div {
        width: 100px;
        height: 100px;
        background-color: aqua;
      }
      /* 
        vw(pc端兼容性不好)
          100vw = 视口宽度 i6 375px
       */
    </style>
  </head>
  <body>
    <div>现场撒</div>
  </body>
</html>
